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  Subjects -> ENGINEERING (Total: 2167 journals)
    - CHEMICAL ENGINEERING (185 journals)
    - CIVIL ENGINEERING (168 journals)
    - ELECTRICAL ENGINEERING (91 journals)
    - ENGINEERING (1176 journals)
    - ENGINEERING MECHANICS AND MATERIALS (356 journals)
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ENGINEERING (1176 journals)            First | 5 6 7 8 9 10 11 12 | Last

Journal of Urban and Environmental Engineering     Open Access  
Journal of Urban Planning and Development     Full-text available via subscription   (Followers: 32)
Journal of Urban Regeneration & Renewal     Full-text available via subscription   (Followers: 17)
Journal of Vibration and Acoustics     Full-text available via subscription   (Followers: 28)
Journal of Visualization     Hybrid Journal   (Followers: 2)
Journal of Volcanology and Seismology     Hybrid Journal   (Followers: 3)
Journal of Wuhan University of Technology-Mater. Sci. Ed.     Hybrid Journal  
Journal of X-Ray Science and Technology     Hybrid Journal  
Journal of Zhejiang University SCIENCE A     Hybrid Journal  
Journal on Chain and Network Science     Full-text available via subscription   (Followers: 3)
Jurnal Teknik ITS     Open Access  
Jurnal Teknologi     Open Access   (Followers: 2)
Karaelmas Science and Engineering Journal     Open Access  
Kerntechnik     Full-text available via subscription  
Kleio     Full-text available via subscription   (Followers: 2)
Landscape and Ecological Engineering     Hybrid Journal   (Followers: 3)
Langmuir     Full-text available via subscription   (Followers: 40)
Leadership and Management in Engineering     Full-text available via subscription   (Followers: 10)
Learning Technologies, IEEE Transactions on     Hybrid Journal   (Followers: 10)
Lighting Research and Technology     Hybrid Journal  
Logic and Analysis     Hybrid Journal  
Logica Universalis     Hybrid Journal  
Lubrication Science     Hybrid Journal  
Machines     Open Access   (Followers: 1)
Machining Science and Technology: An International Journal     Hybrid Journal   (Followers: 3)
Macromolecular Reaction Engineering     Hybrid Journal  
Magazine of Concrete Research     Hybrid Journal   (Followers: 7)
Magdeburger Journal zur Sicherheitsforschung     Open Access  
Magnetics Letters, IEEE     Hybrid Journal   (Followers: 4)
Management and Production Engineering Review     Open Access  
Management Science and Engineering     Open Access   (Followers: 1)
Manufacturing Engineer     Hybrid Journal   (Followers: 3)
Manufacturing Research and Technology     Full-text available via subscription   (Followers: 3)
Marine Technology Society Journal     Full-text available via subscription  
MATEC Web of Conferences     Open Access  
Matériaux & Techniques     Full-text available via subscription   (Followers: 1)
Mathematical Models and Methods in Applied Sciences     Hybrid Journal   (Followers: 2)
Mathematical Problems in Engineering     Open Access   (Followers: 3)
Mathematics of Control, Signals, and Systems (MCSS)     Hybrid Journal   (Followers: 5)
Mauerwerk     Hybrid Journal  
Measurement     Hybrid Journal   (Followers: 2)
Measurement Science Review     Open Access   (Followers: 1)
Meccanica     Hybrid Journal   (Followers: 1)
Mechatronics     Hybrid Journal   (Followers: 4)
Medical and Biological Engineering and Computing     Hybrid Journal   (Followers: 2)
Medical Engineering & Physics     Hybrid Journal   (Followers: 9)
Membrane Science and Technology     Full-text available via subscription   (Followers: 2)
Membrane Technology     Full-text available via subscription   (Followers: 1)
Memetic Computing     Hybrid Journal  
Metabolic Engineering Communications     Open Access  
Metal Powder Report     Full-text available via subscription   (Followers: 5)
Metallurgist     Hybrid Journal   (Followers: 3)
Metaphysica     Hybrid Journal   (Followers: 1)
Metascience     Hybrid Journal   (Followers: 1)
Metrologia     Full-text available via subscription   (Followers: 1)
Microelectronic Engineering     Hybrid Journal   (Followers: 5)
Microelectronics International     Hybrid Journal  
Microelectronics Journal     Hybrid Journal   (Followers: 6)
Microelectronics Reliability     Hybrid Journal   (Followers: 8)
Microfluidics and Nanofluidics     Hybrid Journal   (Followers: 10)
Micromachines     Open Access   (Followers: 2)
MNASSA : Monthly Notes of the Astronomical Society of South Africa     Full-text available via subscription   (Followers: 1)
Modelling and Simulation in Engineering     Open Access   (Followers: 4)
Modern Applied Science     Open Access   (Followers: 1)
Molecular BioSystems     Full-text available via subscription   (Followers: 5)
Molecular Engineering     Hybrid Journal  
Molecular Pharmaceutics     Full-text available via subscription   (Followers: 12)
MRS Bulletin     Full-text available via subscription   (Followers: 5)
MRS Online Proceedings     Full-text available via subscription   (Followers: 1)
Multiagent and Grid Systems     Hybrid Journal  
Multidimensional Systems and Signal Processing     Hybrid Journal  
NANO     Hybrid Journal   (Followers: 8)
Nano Letters     Full-text available via subscription   (Followers: 53)
Nano Research     Hybrid Journal   (Followers: 5)
Nano Reviews     Open Access   (Followers: 17)
Nanopages     Full-text available via subscription   (Followers: 1)
Nanoscale and Microscale Thermophysical Engineering     Hybrid Journal   (Followers: 3)
Nanoscale Systems : Mathematical Modeling, Theory and Applications     Open Access  
Nanoscience and Nanoengineering     Open Access  
Nanoscience and Nanotechnology     Open Access   (Followers: 2)
Nanoscience and Nanotechnology Research     Open Access   (Followers: 1)
Nanotechnologies in Russia     Hybrid Journal   (Followers: 1)
Nanotechnology     Hybrid Journal   (Followers: 10)
Nanotechnology Magazine, IEEE     Full-text available via subscription   (Followers: 18)
Nanotechnology Reviews     Hybrid Journal   (Followers: 5)
Natural Hazards     Hybrid Journal   (Followers: 104)
Nature Nanotechnology     Full-text available via subscription   (Followers: 50)
Naval Engineers Journal     Hybrid Journal   (Followers: 3)
NDT & E International     Hybrid Journal   (Followers: 14)
Nexo Revista Científica     Open Access  
Nigerian Journal of Basic and Applied Sciences     Open Access   (Followers: 2)
Nigerian Journal of Technological Research     Full-text available via subscription  
Nigerian Journal of Technology     Full-text available via subscription  
NIR news     Full-text available via subscription  
Noise Mapping     Open Access  
Nonlinear Dynamics     Hybrid Journal   (Followers: 5)
Nonlinear Engineering : Modeling and Application     Hybrid Journal   (Followers: 1)
Nonlinearity     Full-text available via subscription   (Followers: 2)
Nordic Journal of Science and Technology     Open Access  
Nova Scientia     Open Access  

  First | 5 6 7 8 9 10 11 12 | Last

Journal Cover   Reactive and Functional Polymers
  [SJR: 0.879]   [H-I: 62]   [5 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1381-5148
   Published by Elsevier Homepage  [2811 journals]
  • Controlled Synthesis of Photosensitive Graft Copolymers with High
           Azobenzene-Chromophore Loading Densities in the Main and Side Chains by
           Combining ATRP and ADMET Polymerization
    • Abstract: Publication date: Available online 13 May 2015
      Source:Reactive and Functional Polymers
      Author(s): Liang Ding , Juan Li , Chengshuang Wang , Ling Lin
      Photosensitive graft copolymers containing azobenzene chromophores in the main and side chains were successfully synthesized by combining living atom transfer radical polymerization (ATRP) and acyclic diene metathesis (ADMET) chemistry based on the results of proper heterodifunctional inimer and azobenzene monomer design. The precise copolymer architectural features were manipulated by combining the macromonomer technique and the macroinitiator method. The as-prepared copolymer containing azobenzene chromophores in the main and side chains showed unique reversible isomerization processes, suggesting that the photoisomerization of azobenzene chromophores occured mainly in one of the two types of azobenzene groups in the main or side chains with similar probabilities due to their main and side-on structure.
      Graphical abstract image

      PubDate: 2015-05-15T21:46:50Z
       
  • Immobilization of lecithin on bacterial cellulose nanofibers for improved
           biological functions
    • Abstract: Publication date: Available online 14 May 2015
      Source:Reactive and Functional Polymers
      Author(s): Jing Zhang , Peng Chang , Chen Zhang , Guangyao Xiong , Honglin Luo , Yong Zhu , Kaijing Ren , Fanglian Yao , Yizao Wan
      In an attempt to improve the biological behavior of pristine bacterial cellulose (BC), lecithin (LEC) has been immobilized on the surface of BC nanofibers by solution immersion and subsequent chemical crosslinking with proanthocyanidin (PA). The as-prepared LEC-immobilized BCs (denoted as BC/LECs) were characterized by SEM, FTIR, and XRD, and their dynamic mechanical properties, thermal stability, and hydrophilicity were assessed. The presence of LEC on BC surface was confirmed by SEM and FTIR analyses. It has been found that BC/LECs retain the three-dimensional (3D) porous network structure of pristine BC. The BC/LECs still demonstrate favorable mechanical properties, surface hydrophilicity, and thermal stability. More importantly, preliminary cell studies suggest that the BC/LECs show improved cell behavior over pristine BC.


      PubDate: 2015-05-15T21:46:50Z
       
  • Synthesis of conjugated polymers bearing pendant bipyridine ruthenium
           complexes
    • Abstract: Publication date: May 2015
      Source:Reactive and Functional Polymers, Volume 90
      Author(s): Yuxia Jin , Yingliang Liu , Wenbo Wu , Qiong Wu , Hongyan Gao , Chenxu Wang , Shengang Xu , Shaokui Cao
      Conjugated polymers bearing pendant bipyridine groups, PM1PT-x, were synthesized in high yield from a carefully designed dibromocarbazole monomer M1 using a Suzuki coupling reaction with a phenothiazine diborate monomer. PM1PT-x, where x is the mole percentage of M1 in the total feed of dibromo-monomers and varied to levels of 25%, 50%, 75% and 100%, was reacted with a ruthenium complex to yield conjugated polymers bearing pendant bipyridine ruthenium complexes, PM1PT-x-Ru. The introduction of ruthenium complexes extended the absorption of PM1PT-x-Ru to the visible light region. Furthermore, these polymers demonstrated sufficient stability and suitable energy levels to potentially be highly efficient photoactive materials for polymeric solar cells.


      PubDate: 2015-05-11T21:29:20Z
       
  • Editors and Editorial Board
    • Abstract: Publication date: May 2015
      Source:Reactive and Functional Polymers, Volume 90




      PubDate: 2015-05-11T21:29:20Z
       
  • Challenging activated monomer ring-opening polymerization for direct
           synthesis of thiol end-functionalized polyesters
    • Abstract: Publication date: May 2015
      Source:Reactive and Functional Polymers, Volume 90
      Author(s): Maksym A. Kryuchkov , Ying Hua Qi , Iryna I. Perepichka , Carole Pelletier , Aurelie Regnaud , Zhengji Song , Sunil K. Varshney
      A direct, non-enzymatic procedure for the synthesis of thiol-functionalized polylactones was developed and optimized by using 2-mercaptoethanol, the simplest unprotected thiol-containing initiator for cationic ring-opening polymerization, catalyzed by HCl and methanesulfonic acid in dichloromethane solutions. Thiol-functionalized polylactones with a molecular weight of up to approximately 5000Da were obtained in a controlled manner. It was observed that acid can play the dual role of activator and initiator, and for the first time, it was shown that abundant HCl and/or ambient temperature lead to the formation of undesired α-carboxy-ω-chloro-functionalized polylactones that form in parallel with the targeted thiol-functionalized ones. A plausible pathway towards the formation of chlorinated products is proposed based on an active-chain-end mechanism, and the procedure was optimized to eliminate its contribution to the polymerization process, thus allowing for the activated-monomer mechanism to prevail. Molecular weight characterization was performed using 1H NMR and size-exclusion chromatography. The results indicate that the polymers obtained under optimized conditions possess high SH functionality and moderate polydispersity, and that ring-opening polymerization proceeded in a controlled fashion. The proposed method allows for the preparation of metal free materials readily suitable for biomedical and/or electronic applications.


      PubDate: 2015-05-11T21:29:20Z
       
  • Antibacterial activity of chitosan grafting nisin: Preparation and
           characterization
    • Abstract: Publication date: Available online 2 May 2015
      Source:Reactive and Functional Polymers
      Author(s): Xiaoming Zhu , Huan Wu , Jing Yang , Jun Tong , Jiayan Yi , Zhihai Hu , Jin Hu , Tan Wang , Lihong Fan
      Nisin grafted chitosan was prepared by using microbial transglutaminase as biocatalyst. The transglutaminase-catalyzed reaction displayed high efficiency, high selectivity, mild reaction condition and environmental friendliness. The results revealed that the degree of substitution (DS) of nisin-chitosan could be controlled by adjusting the reaction time, the reaction temperature and the molar ratio of nisin to chitosan. And nisin-chitosan in different pH showed excellent solubility. In addition, in vitro antibacterial activity assessment, nisin-chitosan with the concentration of 0.008 mg/mL showed pronounced inhibitory effect against gram-positive bacteria (S.aureus, B.subtilis) and gram-negative bacteria (E.coli). Furthermore, L929 mouse fibroblasts were cultured with nisin-chitosan, and the methylthiazol tetrazolium (MTT) assay showed that nisin-chitosan with the concentration from 0.005 to 0.01 mg/mL displayed low toxicity. The results may contribute to finding the application of nisin-chitosan in pharmaceutical and food industry fields.


      PubDate: 2015-05-11T21:29:20Z
       
  • Separation of americium from complex radioactive mixtures using a BTPhen
           extraction chromatography resin
    • Abstract: Publication date: Available online 8 May 2015
      Source:Reactive and Functional Polymers
      Author(s): Matthew A. Higginson , Olivia J. Marsden , Paul Thompson , Francis R. Livens , Sarah L. Heath
      Extraction chromatography (EC) resins are widely used in analytical radiochemical separations, in particular for actinide separation. However, there is currently limited choice for separation of americium using EC, with DGA (N,N,N’,N’-tetra-n-octyldiglycolamide) resin being the preferred option. Here, we describe preparation and testing of a covalently-linked EC resin utilising a triazine soft N-donor (Me4BTPhen) extractant for americium extraction. The resin was generated by conjugation of a Me4BTPhen derivative with poly(vinylbenzyl) chloride to generate PVB-Me4BTPhen. PVB-Me4BTPhen was shown to extract americium from a complex matrix simulating nuclear forensic samples, and containing lanthanides, actinides and matrix elements with high Am (III) recovery (>90%) and low extraction of other elements, and provides an alternative to the currently used BTPhen liquid-liquid separation process for Am (III) extraction.


      PubDate: 2015-05-11T21:29:20Z
       
  • Stimuli responsive carbon nanocomposite hydrogels with efficient
           conducting properties as a precursor to bioelectronics
    • Abstract: Publication date: May 2015
      Source:Reactive and Functional Polymers, Volume 90
      Author(s): Priyanka Dutta , Narendra Nath Dass , Neelotpal Sen Sarma
      Stimuli responsive conducting carbon nanocomposite hydrogels were synthesized from glycerol methacrylate, ethylene glycol methacrylate and diethylene glycol methacrylate by thermal polymerization techniques. Carbon nanoparticles of size <50nm were incorporated into the polymer at a concentration of 0.005% (w/w) during synthesis. The hydrogels were characterized by Fourier Transform-Infrared Spectroscopy, thermogravimetric analysis, Scanning Electron Microscopy techniques and X-ray diffraction study. The hydrogels have excellent absorption properties in aqueous solvents which is sensitive to pH, temperature, ionic strength, etc. For instance, the pH sensitive swelling behavior of Polyglycerylmethacrylate-carbon nanocomposite increases from acidic medium (SR∼24, pH=3) to basic medium (SR∼130, pH=12). The hydrogels also showed significant swelling behavior in presence of different biological samples such as folic acid, uric acid, DNA and RNA. The electrical impedance value decreases to a large extent after the addition of carbon nanoparticles into the gels. It was observed that the conductivity rises to a maximum of about 1000 folds in the nanocomposite hydrogels. The increase in electrical conductivity is also verified by current–voltage measurements.


      PubDate: 2015-05-11T21:29:20Z
       
  • Cross-linking of cellulose and poly(ethylene glycol) with citric acid
    • Abstract: Publication date: May 2015
      Source:Reactive and Functional Polymers, Volume 90
      Author(s): Pamela de Cuadro , Tiina Belt , Katri S. Kontturi , Mehedi Reza , Eero Kontturi , Tapani Vuorinen , Mark Hughes
      A novel approach to modifying native cellulosic fibres with poly(ethylene glycol) (PEG) impregnation and simultaneous cross-linking by citric acid (CA) was investigated. To understand the contributions of different components in the system, control references with just CA and cellulosic fibres (filter paper) were studied. The effect of sodium hypophosphite as a catalyst was also assessed. The results revealed that ester bonds are indeed formed in the cellulose–PEG–CA reaction system, as indicated by weight percentage gain (WPG) and FTIR analysis. The best results were achieved by using 5% CA and 10% PEG (calculated as weight-% from cellulose). In the reaction, the environmentally friendly CA prevents PEG from being leached out of cellulose during washing, resulting in promising future applications in dimensionally stabilized products based on cellulosic fibres.


      PubDate: 2015-05-11T21:29:20Z
       
  • The potential of Kraft black liquor to produce bio-based
           emulsion-templated porous materials
    • Abstract: Publication date: May 2015
      Source:Reactive and Functional Polymers, Volume 90
      Author(s): Amandine Foulet , Marc Birot , Guido Sonnemann , Hervé Deleuze
      Emulsion-templated porous monoliths based on castor oil-in-black liquor and on 1,2-dichloroethane-in-black liquor medium internal phase emulsions have been prepared in order to evaluate a possible valorisation of that undervalued by-product of the paper mill Kraft process. The cross-linking behaviour of the different polymers originally contained in the black liquor was investigated. It appears that both lignin and hemicellulose fragments are involved. Characterisation of the monoliths by scanning electronic microscopy and mercury intrusion porosimetry showed that using either castor oil or 1,2-dichloroethane allowed to obtain macrocellular morphology along with a high porosity. However, higher concentration of the internal phase is possible in emulsions prepared with 1,2-dichloroethane than with castor oil, leading to more attractive materials from both chemical and environmental aspects.


      PubDate: 2015-05-11T21:29:20Z
       
  • Refractive index changes in polyacrylates bearing alkyl sulfur groups
           through the sulfur oxidation reaction
    • Abstract: Publication date: June–July 2015
      Source:Reactive and Functional Polymers, Volumes 91–92
      Author(s): Jae Young Jang , Jung Yun Do
      Four polyacrylates with sulfur-containing side chains were prepared to examine the changes in refractive index (RI) induced by sulfur oxidation. Linear alkyl sulfides and alicyclic sulfides, such as 1,3-dithiolane and 1,4-dithiane, were introduced to impart large RIs to polyacrylates. Oxidation of the sulfur polymers by O3 and m-chloroperoxybenzoic acid led to the formation of the corresponding sulfoxide and sulfone polymers, respectively. Sulfur oxidation occurred completely, which was highlighted by the oxidized polymer exhibiting a refractive index comparable to a polymer that was synthesized using a sulfone monomer. The RI of the linear sulfur polymer increased and decreased due to the formation of sulfoxide and sulfone polymers, respectively. The Abbe number of the polymer with a linear sulfide side chain was 33.4, which increased to 48.7 after oxidation.


      PubDate: 2015-05-11T21:29:20Z
       
  • Extraction of chitosan from Aspergillus niger mycelium and synthesis of
           hydrogels for controlled release of betahistine
    • Abstract: Publication date: June–July 2015
      Source:Reactive and Functional Polymers, Volumes 91–92
      Author(s): Gustavo Muñoz , Carlos Valencia , Nora Valderruten , Eduardo Ruiz-Durántez , Fabio Zuluaga
      Chitosan was extracted from the fungus Aspergillus niger, an alternative source of chitin that is widely available as a byproduct of the industrial production of citric acid. Chitosan with deacetylation degree (DD) of 73.6% was characterized by elemental analysis, capillary viscometry (molecular weight of 1.9×105 g/mol), Fourier transform infrared (FTIR), nuclear magnetic resonance (1H NMR, 13C NMR and 15N NMR) spectroscopies, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Fungal chitosan was crosslinked with glutaraldehyde and glutaric acid to obtain hydrogels. Chitosan hydrogels were characterized by FTIR and by scanning electron microscopy (SEM), which showed that these materials have irregular, polydisperse, and interconnected pores. Kinetic studies of the release of betahistine from the swollen hydrogels showed a Fickian diffusion mechanism. Finally, hydrolytic degradation of chitosan hydrogels under simulated physiological conditions (pH 7.4 and 37°C) was investigated as well as in vivo biocompatibility tests using New Zealand white rabbits as animal models.


      PubDate: 2015-05-11T21:29:20Z
       
  • PLGA/SF blend scaffolds modified with plasmid complexes for enhancing
           proliferation of endothelial cells
    • Abstract: Publication date: June–July 2015
      Source:Reactive and Functional Polymers, Volumes 91–92
      Author(s): Li Yu , Yakai Feng , Qian Li , Xuefang Hao , Wen Liu , Wei Zhou , Changcan Shi , Xiangkui Ren , Wencheng Zhang
      Biomimetic scaffolds have been investigated for vascular tissue engineering for many years. However, the design of an ideal biodegradable vascular scaffold is still in progress. The optimization of poly(lactide-co-glycolide)/silk fibroin (PLGA/SF) blend composition was performed to provide the designed scaffolds with adequate mechanical properties and favorable biocompatibility for the intended application. By systematically varying the weight ratio of PLGA and SF, we could control fiber diameter and hydrophilicity as well as mechanical properties of the fibrous scaffolds. These scaffolds with a weight ratio of PLGA/SF at 70/30 exhibited excellent performance, such as tensile strength of 1.5±0.1MPa, and elongation at break of 77.4±6.4%. Therefore, PLGA/SF scaffold with a weight ratio of 70/30 was chose as the matrix because it matches at best the mechanical demands for application in vascular tissue engineering. In order to promote the endothelialization of electrospun scaffolds, we used pEGFP-ZNF580 plasmid (pZNF580) complexes to modify the electrospun scaffolds by electrospraying technique. pZNF580 complexes were prepared from pZNF580 and microparticles (MPs) of amphiphilic copolymer methoxy-poly(ethylene glycol)-block-poly(3(S)-methyl-2,5-morpholinedione-co-glycolide)-graft-polyethyleneimine. Negatively charged PLGA/SF fibers adsorbed the positively charged MPs via physical deposition and electrostatic force. Scanning electron microscope image indicated the forming of composite scaffold and MPs did not change fiber’s shape and 3-D structure. Cell culture experiments demonstrated that the scaffolds modified with MPs/pZNF580 complexes could promote human umbilical vein endothelial cell growth and inhibit human umbilical artery smooth muscle cell proliferation. Our results indicated that the composite scaffolds with MPs/pZNF580 complexes could be used as a potential scaffold for vascular tissue engineering.


      PubDate: 2015-05-11T21:29:20Z
       
  • Adamantane-based epoxy resin and siloxane-modified adamantane-based epoxy
           resin: Characterization of thermal, dielectric and optical properties
    • Abstract: Publication date: June–July 2015
      Source:Reactive and Functional Polymers, Volumes 91–92
      Author(s): C.W. Tsai , K.H. Wu , C.C. Yang , G.P. Wang
      An adamantane-based epoxy resin (ADEP) and a siloxane-modified adamantane-based epoxy resin (Siloxane-ADEP) were synthesized, and their chemical structures were confirmed from FT-IR, 1H, 13C and 29Si NMR spectroscopy measurements. The morphological, thermal, dielectric and optical properties of ADEP and Siloxane-ADEP were studied. The introduction of the adamantane group into the chain of the epoxy resin resulted in improvements in the thermal, mechanical and dielectric properties. These results can be explained in terms of the tricyclic hydrocarbon of the adamantane in a diamond lattice structure and the movement of polymer chains being limited by chair-form cyclohexane rings, resulting in an immobile epoxy structure. Moreover, Siloxane-ADEP exhibited good thermal, mechanical and dielectric properties that were similar to those of epoxy resin, and its better processability may extend its application to electronic packing materials. The UV–Vis transmission spectra revealed that the adamantane-containing epoxy membranes exhibited novel ultraviolet light-filtering properties.


      PubDate: 2015-05-11T21:29:20Z
       
  • Influence of solvent characteristics in triaxial electrospun fiber
           formation
    • Abstract: Publication date: May 2015
      Source:Reactive and Functional Polymers, Volume 90
      Author(s): Abdurizzagh Khalf , Kumar Singarapu , Sundararajan V. Madihally
      Triaxial electrospinning is a novel method for fabrication of multilayered nano and microsize fibers with desirable features for particular applications. Since the effect of solvent volatilities in each layer and relative polymer molecular weights on uniform encapsulation of the core polymer process is not well understood, we evaluated (i) the role of solvent volatilities, and (ii) molecular weights using cellulose acetate (CA, 30kDa), polycaprolactone (PCL, 45kDa and 80kDa), mineral oil, and polyvinyl alcohol (PVA, 30kDa and 100kDa). Different solvent mixtures were evaluated based on the boiling points determined using a simulator. Inner mineral oil was selectively removed to form Hollow fibers. Analysis of chemical compositions using FT-IR and DSC revealed the presence of each component. 24-h viability of human umbilical vein endothelial cells indicated the formed fibers were not toxic. Scanning electron micrographs indicated the formation of triaxial structured fiber of outer hydrophobic PCL/CA/Hollow, PCL/PVA/Hollow and outer hydrophilic CA/PCL/Hollow fibers. Tensile tests (both wet and dry) revealed that PCL/CA/Hollow fibers had increased stiffness and load carrying capacity than CA/PCL/Hollow fibers. Successful fiber formation was dependent on ensuring that the outer shell formed first i.e., the relative solvent volatility of encapsulating core polymer to lower than that of the shell polymer.


      PubDate: 2015-05-11T21:29:20Z
       
  • Preparation of monodispersed porous polyacrylamide microspheres via phase
           separation in microchannels
    • Abstract: Publication date: Available online 30 April 2015
      Source:Reactive and Functional Polymers
      Author(s): Song Guo , Tong Yao , Chongqing Wang , Changfeng Zeng , Lixiong Zhang
      We report on the formation of polyacrylamide (PAM)/polyethylene glycol (PEG) core/shell droplets in a microchannel via the polymerization-induced phase separation of an acrylamide (AM)/PEG aqueous system. Monodispersed porous PAM microspheres were prepared from the PAM/PEG core/shell droplets, and we examined the effects of experimental parameters on the phase separation process and on the particle size and pore structure of the resulting PAM microspheres. PAM microspheres could be readily obtained with adjustable particle sizes and porosities by altering the PEG and crosslinker contents and by using PEG with different molecular weights. The relation between the swelling value and porosity is correlated.


      PubDate: 2015-05-11T21:29:20Z
       
  • Manufacture and Performance of Ethylamine Hydroxyethyl Chitosan/Cellulose
           Fiber in N-methylmorpholine-N-oxide System
    • Abstract: Publication date: Available online 28 April 2015
      Source:Reactive and Functional Polymers
      Author(s): Xin Jin , Xiaofei Liu , Qianwen Liu , Yuan Li
      Ethylamine hydroxyethyl chitosan (EHC), a novel chitosan derivative which is soluble in aqueous N-methylmorpholine-N-oxide (NMMO) and antibacterial to Escherichia coli (E. coli) was synthesized. The structure, solubility and antibacterial capability of EHC were investigated. Results demonstrated the potential application for EHC in manufacture of antibacterial EHC/cellulose Lyocell fiber. Through environment-friendly Lyocell process in aqueous NMMO, the EHC/cellulose fiber was successfully fabricated and the various properties of EHC/cellulose fiber were studied. Results showed the EHC/cellulose fiber exhibited favorable consistency, antibacterial activity, mechanical properties and water retention compared with the fiber without EHC.


      PubDate: 2015-05-11T21:29:20Z
       
  • Removal of Reactive Blue 21 onto magnetic chitosan microparticles
           functionalized with polyamidoamine dendrimers
    • Abstract: Publication date: Available online 27 April 2015
      Source:Reactive and Functional Polymers
      Author(s): Peng Wang , Qianyun Ma , Dongying Hu , Lijuan Wang
      Chitosan/poly(amidoamine) (MCS/PAMAM) microparticles were prepared as magnetic adsorbents for removal of Reactive Blue 21 (RB 21) dye from aqueous solution. Characterization of these particles was carried out using scanning electron microscopy, Fourier transform-infrared spectroscopy, X-ray diffractometry and vibrating sample magnetometry. The results indicate that the magnetic chitosan microparticles (MCS) were functionalized with PAMAM dendrimers and maintained its intrinsic magnetic properties. The effects of initial pH, adsorbent dose, initial concentration, contact time and temperature on adsorption were investigated. Kinetic studies showed that the dye adsorption process followed a pseudo-second-order kinetic model but that the adsorption rate was also influenced by intraparticle diffusion. Equilibrium adsorption isotherm data indicated a good fit to the Langmuir isotherm. The maximum adsorption capacities obtained from the Langmuir model were 555.56, 588.24, 625.00 and 666.67 mg g–1 at 303, 313, 323 and 333 K, respectively. The thermodynamic parameters revealed the feasibility, spontaneity and endothermic nature of the adsorption. Recycling experiments confirmed the relative reusability of the adsorbent.


      PubDate: 2015-05-11T21:29:20Z
       
  • Selective removal of ATP degradation products from food matrices I: Design
           and characterization of a dummy molecularly imprinted specific sorbent for
           Hypoxanthine
    • Abstract: Publication date: Available online 24 April 2015
      Source:Reactive and Functional Polymers
      Author(s): Aurora Lasagabaster Latorre , M Concepción Cela Pérez , Sara Fernández Fernández , J.M. López Vilariño , M.V. González Rodríguez
      Specific molecularly imprinted polymers (MIPs) for hypoxanthine (HYP) recognition in aqueous organic media have been developed based upon UV, FTIR and 1H-NMR prepolymerization studies in conjunction with batch rebinding UPLC analyses. The MIPs, which used the template mimics caffeine (CAF) and theophylline (TPH), are prepared in CHCl3 by one step precipitation polymerization from acrylamide (AM), 2-hydroxiethyl-methacrylate (HEMA) and methacrylic acid (MAA) as functional monomers, whereas ethylene glycol dimethacrylate (EGDMA), divinylbenzene (DVB) and trimethylolpropane triacrylate (TMPTA) as cross-linkers. The magnitude of the pre-polymerisation binding constants between TPH and AM, MAA and HEMA is consistent with the complex stoichiometry (1:2 and 1: 1) and number of interaction points (3-, 2-, 1- hydrogen bonded motif). The strong (1:2) complex between TPH and AM (K11 =3.36×104M−1 and K12 =1.33×102M−1) makes the corresponding MIP the most suitable for HYP recognition. The best performance of the TPH: AM: EGDMA (1:4: 20) MIP is reflected in the high IF and high weighted average affinity based on the Freundlich isotherm. Further polymer characterization by ATR-FTIR, elemental analysis, surface area analysis (BET), swelling and SEM yield vital information regarding the degree of polymerization, real monomer: crosslinker ratio, morphology, pore size distribution plus conformational changes on exposure to different solvents.


      PubDate: 2015-05-11T21:29:20Z
       
  • Exploring the post-polymerization modification of side-chain amino acid
           containing polymers via Michael addition reactions
    • Abstract: Publication date: Available online 23 April 2015
      Source:Reactive and Functional Polymers
      Author(s): Amal Narayanan , Binoy Maiti , Priyadarsi De
      An efficacious protocol for the aza-Michael addition of a C-terminus modified phenylalanine side-chain containing polymer (Michael donor) was demonstrated with various Michael acceptors. The aza-Michael addition reactions were carried out at 50 °C in anhydrous methanol, which is a protic solvent, to enhance the advancement of the reactions. 1H and inverse gated 13C NMR spectroscopy were utilized to qualitatively deliver comprehensive data on the reaction progress. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) provided quantitative information about the modification of the polymer. The extent of change in the aza-Michael addition varied with different Michael acceptors and decreased in the order of acrylate > acrylamide > methacrylate. The present study opens up a library of polymers with functional modifications in the side-chain.
      Graphical abstract image

      PubDate: 2015-05-11T21:29:20Z
       
  • Editors and Editorial Board
    • Abstract: Publication date: April 2015
      Source:Reactive and Functional Polymers, Volume 89




      PubDate: 2015-05-11T21:29:20Z
       
  • Temperature-sensitive hydrogel modified by polymerizable liquid crystal
           AAc-Brij-58: Optical and protein adsorption/desorption behaviors
    • Abstract: Publication date: April 2015
      Source:Reactive and Functional Polymers, Volume 89
      Author(s): Pengfei Liu , Wenjun Gao , Qingsong Zhang , Kun Chen , Juan Zhang , Li Chen , Xiaoyong Zhang , Ke Wang
      To avoid template-like action of polyoxyethylene 20 cetyl ether (Brij-58) in hydrogel matrix, a polymerizable liquid crystal AAc-Brij-58 based acrylic acid (AAc) and Brij-58, and poly(NIPAm-co-AAc-Brij-58) (ACHX) hydrogels based on N-isopropylacrylamide (NIPAm) and AAc-Brij-58 were synthesized by esterification and free-radical polymerization. The chemical structures of resulting ACHX hydrogels were confirmed by FTIR and 1H NMR. The optical property of ACHX pre-polymerization solution was monitored by ultraviolet–visible spectrophotometry (UV/Vis). The pore structure was observed by scanning electron microscopy (SEM). The adsorption and desorption behaviors of Bovine Serum Albumin (BSA) were investigated by temperature-oscillating between 37°C and 25°C. The result shows that AAc-Brij-58 and ACHX hydrogels have been successfully synthesized. With increasing mass percent of AAc-Brij-58/NIPAm from 0 to 10wt%, the transparency of ACH01-10 hydrogel decreases to 0 at 20, 17, 14, 12 and 16min, respectively. The interior of ACHX hydrogels presents honeycomb structure with thick pore wall with pore size from 120 to 600μm, but shows vent-like structure on the outer surface after copolymerization by AAc-Brij-58. The adsorption and desorption of ACHX hydrogels exhibit reversible temperature oscillation responsibility between 37°C and 25°C. As mass percent of AAc-Brij-58/NIPAm is 1wt%, ACH01 hydrogel presents highest adsorbed BSA amount, about 1090±24mg/g at 37°C. After desorption at 25°C, columniform BSA aggregates on the surface of ACHX hydrogels were not observed.


      PubDate: 2015-05-11T21:29:20Z
       
  • Fabrication of thermosensitive, star-shaped
           poly(L-lactide)-block-poly(N-isopropylacrylamide) copolymers with
           porphyrin core for photodynamic therapy
    • Abstract: Publication date: April 2015
      Source:Reactive and Functional Polymers, Volume 89
      Author(s): Xiao-Hui Dai , Hua Jin , Mei-Hong Cai , Hao Wang , Zhi-Ping Zhou , Jian-Ming Pan , Xiao-Hong Wang , Yong-Sheng Yan , Dong-Ming Liu , Lin Sun
      Thermosensitive, star-shaped porphyrin-cored poly(L-lactide)-block-poly(N-isopropylacrylamide) (SPPLA–PNIPAM) was synthesized via ring-opening polymerization (ROP) and reversible addition–fragmentation chain transfer polymerization (RAFT). The composition and properties of copolymer were discussed based on the results of NMR, IR and GPC. With PNIPAM block length decreasing, the morphology of SPPLA–PNIPAM copolymer in aqueous solution transformed hierarchically from spherical micelles through wormlike micelles to vesicles, and the lower critical solution temperatures (LCST) of the copolymer solutions were determined to be 37.9°, 37.2°, 35.9°, respectively. The in vitro study indicated that SPPLA–PNIPAM showed no significant dark cytotoxicity at concentrations up to 128μg/mL, while showed apparent phototoxicity toward BEL-7402 cancer cells. Considering a high singlet oxygen quantum yield and suitable nominal physiologic LCST, it is expected that the SPPLA–PNIPAM copolymer is a promising stimulus-responsive candidate which has a potential application in photodynamic therapy (PDT).


      PubDate: 2015-05-11T21:29:20Z
       
  • Poly(3-hydroxyalkanoate)-grafted carbon nanotube nanofillers as
           reinforcing agent for PHAs-based electrospun mats
    • Abstract: Publication date: April 2015
      Source:Reactive and Functional Polymers, Volume 89
      Author(s): C. Mangeon , S. Mahouche-Chergui , D.L. Versace , M. Guerrouache , B. Carbonnier , V. Langlois , E. Renard
      Poly(3-hydroxyalkanoate)s, PHAs, have been covalently grafted onto the surface of multi-walled carbon nanotubes, MWCNTs, providing nanofillers (MWCNT-graft-PHAs) with enhanced compatibility and reinforcement effect towards PHAs. MWCNTs were first modified by in-situ generated diazonium cations obtained from a hydroxyl-containing aniline derivative, yielding MWCNTs with reactive hydroxyl surface groups, MWCNT-OH. Then, MWCNT-graft-PHAs were obtained by direct, i.e. without using any catalyst, transesterification approach. The successful chemical modification of MWCNTs surface was evidenced by Raman spectroscopy and XPS analysis confirming the covalent grafting of PHA on MWCNT. 3-Dimension mats were further produced through electrospinning of a PHA/MWCNT-graft-PHA solution providing nanocomposites with well-defined nanofibrous morphology. No aggregation of the MWCNTs was evidenced by SEM attesting that the grafting of PHA onto MWCNT improved their dispersion within the PHA matrix and consequently, the properties of the corresponding nanomaterials. Indeed, mechanical analysis results have shown that nanofibers loaded with MWCNT-graft-PHA (3wt%) displayed excellent properties with an increase (+41%) of the tensile strain at break without any decrease of the high elastic modulus as compared to pristine PHA (131MPa).


      PubDate: 2015-05-11T21:29:20Z
       
  • Macrocycle-functionalized polystyrene beads as specific absorbers
    • Abstract: Publication date: April 2015
      Source:Reactive and Functional Polymers, Volume 89
      Author(s): Pernilla Sund , Carl-Eric Wilén
      Crosslinked polystyrene beads were first functionalized with phenacyl ester linkers, and a series of four macrocycles with different ring sizes were synthesized from these linkers. The macrocycles were built from amide-linked monomers coupled by conventional peptide-synthesis methods. Annulation was achieved by copper(I)-catalyzed intramolecular azide–alkyne cycloaddition to give triazole linked macrocycles. The macrocycles were cleaved from the polymer beads with hydrazinolysis or saponification. The structures of macrocycles were confirmed by high-resolution nuclear magnetic resonance (NMR) and liquid chromatography–mass spectrometry (LC–MS) analysis. The ability of the polymers to selectively bind compounds from a mixture of aromatic derivatives in ethanol was tested. The prepared polystyrene supported macrocycles were found to selectively bind bromophenol blue and bromocresol green non-covalently with an association constant of 160–490M−1.
      Graphical abstract image

      PubDate: 2015-05-11T21:29:20Z
       
  • Preparing valuable renewable nanocomposite films based exclusively on
           oceanic biomass – Chitin nanofillers and chitosan
    • Abstract: Publication date: April 2015
      Source:Reactive and Functional Polymers, Volume 89
      Author(s): Asier M. Salaberria , Rene Herrera Diaz , Jalel Labidi , Susana C.M. Fernandes
      Added-value bionanocomposite films were obtained using exclusively oceanic biomass, i.e. chitin nanofillers (nanocrystals- CHNC and nanofibers- CHNF) and chitosan (CS) isolated from Cervimunida johni (yellow lobster) wastes. From these raw materials two sets of bionanocomposite films (CS/CHNC and CS/CHNF) using CS as matrix and CHNC or CHNF as functional agents were prepared by solvent evaporation-casting approach. The bionanocomposite films’ chemistry, structure, mechanical and thermal properties and fungal growth inhibition toward A. niger were analyzed, and the effect of the CHNC and CHNF on the final properties of CS-based bionanocomposite films was evaluated and compared. The data demonstrated that the final properties were dependent of the content and nano nature (size and shape) of chitin nanofillers incorporated in the CS matrix. The CS-based bionanocomposite films reinforced with CHNF showed superior mechanical properties than those prepared with CHNC. Moreover, antifungal assessment demonstrated that CS/CHNF bionanocomposite films presented an inhibitory effect (FGI >80%) against A. Niger. Unquestionably, these bionanocomposite films show a great potential to be used in packaging applications and medical devices.


      PubDate: 2015-05-11T21:29:20Z
       
  • Modifying polyester surfaces with incompatible polymer additives
    • Abstract: Publication date: April 2015
      Source:Reactive and Functional Polymers, Volume 89
      Author(s): Christopher D. James , Christopher Jeynes , Nuno P. Barradas , Luke Clifton , Robert M. Dalgliesh , Rebecca F. Smith , Stephen W. Sankey , Lian R. Hutchings , Richard L. Thompson
      Surface modification of amorphous PET in incompatible blends is demonstrated using fluorocarbon end-functional polystyrenes. Contact angles with water and decane were consistent with high levels of surface fluorocarbon, even for spin-cast films with no further processing required. Hydrophobicity and lipophobicity were further increased by annealing above the glass transition temperature. High resolution depth profiling using complementary ion beam analysis and specular neutron reflectometry has enabled accurate characterisation of the composition profile of the additive including the minimum in additive concentration found just below the surface enriched layer. This analysis quantified the very low compatibility between the modifying polymer and the amorphous PET and was consistent with the highly segregated nature of the adsorbing species and its sharp interface with the subphase. For these incompatible polymer blends, surfaces enriched with the surface active polymer could coexist at equilibrium with extremely low (∼0.4%) bulk loadings of the additive. This suggests that for thicker films at even lower additive concentrations than the minimum 1% that we studied, it may be possible to achieve efficient surface modification. However, at this concentration, the efficiency of surface modification is limited by the processing conditions. Finally we note that in higher loadings of surface active additive there is clear evidence for lateral phase separation into patterned domains of differing composition. The enhancement in surface properties is due to local reorganisation rather than bulk redistribution of the components within the film, as the composition versus depth distributions of the polymer blend components was observed to be relatively unaffected by annealing.
      Graphical abstract image

      PubDate: 2015-05-11T21:29:20Z
       
  • Editors and Editorial Board
    • Abstract: Publication date: March 2015
      Source:Reactive and Functional Polymers, Volume 88




      PubDate: 2015-05-11T21:29:20Z
       
  • Electroactive shape memory performance of polyurethane/graphene
           nanocomposites
    • Abstract: Publication date: March 2015
      Source:Reactive and Functional Polymers, Volume 88
      Author(s): J.T. Kim , H.J. Jeong , H.C. Park , H.M. Jeong , S.Y. Bae , B.K. Kim
      A series of electroactive shape memory polyurethane (SMPU) nanocomposites were synthesized from poly(tetramethylene ether) glycol (PTMG), 4,4-methylenebis(phenyl isocyanate) (MDI) and 1,3-butandiol (1,3-BD) with the addition of various amounts of thermally reduced graphenes (TRG) which were chemically modified with allyl isocyanate (iTRG). The effects of iTRG on electroactive shape recovery behaviors as well as the conventional direct heat actuated SMPU material have been studied in terms of morphological, thermal, mechanical, electrical properties and thermomechanical cyclic behavior. It was found that significant increases in electrical conductivity and temperature were obtained high iTRG contents (>2%) to electrically actuate the nanocomposite, along with large increases in glass transition temperature (T g) and initial modulus with a dramatic drop in elongation at break.


      PubDate: 2015-05-11T21:29:20Z
       
  • Preparation of core–shell structural surface molecular imprinting
           microspheres and recognition of l-Asparagine based on [N1111]Asn ionic
           liquid as template
    • Abstract: Publication date: March 2015
      Source:Reactive and Functional Polymers, Volume 88
      Author(s): Ji Li , Xiaoling Hu , Ping Guan , Renyuan Song , Xiangrong Zhang , Yimei Tang , Chaoli Wang , Liwei Qian
      Core–shell structural surface imprinting microspheres were prepared by a simple and effective method. This method combined reversible addition–fragmentation chain transfer (RAFT) with distillation precipitation polymerization RAFT reagent-containing microspheres on the surface. Tetramethylammonium asparagine ([N1111]Asn) ionic liquid or l-Asn, 4-vinylpyridine (4-VP), ethylene glycol dimethacrylate (EGDMA), and RAFT reagent-containing microspheres on the surface were used as template, functional monomer, cross-linker, and chain transfer agent (CTA), respectively. Two kinds of imprinted polymer were obtained, namely, AsnIL-MIPs and Asn-MIPs. The morphology and structure of the polymers were characterized by scanning electron microscopy and Fourier-transform infrared spectroscopy. The binding and selective recognition properties of l-Asn and its analogs were investigated in aqueous solution. Compared with l-Asn as template molecule, AsnIL-MIPs showed faster binding speed and better selective recognition. The binding reached saturation after 1h, and the selective recognition factor (α) reached 5.28 and 4.26 for the template against l-Asp and l-Arg, respectively. AsnIL-MIPs showed an improved binding rate, binding affinity, and significantly increased recognition.
      Graphical abstract image

      PubDate: 2015-05-11T21:29:20Z
       
  • Synthesis and characterization of four- and six-arm star-shaped
           poly(ε-caprolactone)-b-poly(N-vinylcaprolactam): Micellar and core
           degradation studies
    • Abstract: Publication date: March 2015
      Source:Reactive and Functional Polymers, Volume 88
      Author(s): G.D. García-Olaiz , K.A. Montoya-Villegas , A. Licea-Claverie , N.A. Cortez-Lemus
      Star-shaped copolymers with four and six poly(ε-caprolactone)-block-poly(N-vinylcaprolactam) (S(PCL-b-PNVCL)) arms were successfully synthesized by combining ring opening polymerization (ROP) of ε-caprolactone (CL) and reversible addition-fragmentation chain transfer (RAFT) polymerization of N-vinylcaprolactam (NVCL). The resulting star copolymers were characterized using 1H NMR, GPC and UV–vis. The numbers of arms in the star-shaped PCL-b-PNVCL block copolymers were demonstrated using degradation studies under acidic conditions, and the individual PNVCL chains were characterized by GPC and 1H NMR. In aqueous solution, star-shaped PCL-b-PNVCL block copolymers self-assembled into large aggregates or micelles with sizes varying from 54 to 300nm, depending on the molecular weight of the copolymer and the relative lengths of the hydrophobic and hydrophilic segments. Micelles were characterized by atomic force microscopy (AFM), dynamic light scattering (DLS) and scanning electron microscopy (SEM).


      PubDate: 2015-05-11T21:29:20Z
       
  • Fabrication of copper coated polymer foam and their application for
           hexavalent chromium removal
    • Abstract: Publication date: March 2015
      Source:Reactive and Functional Polymers, Volume 88
      Author(s): Chunchuang Li , Zhongjie Du , Wei Zou , Hangquan Li , Chen Zhang
      The polymer foam coated with zero-valent copper (Cu0) was designed and prepared for the removal of hexavalent chromium (Cr(VI)) in water. Firstly, porous poly(tert-butyl acrylate) was fabricated by concentrated emulsion polymerization and then acrylic acid groups were generated on the surface of foam by hydrolysis reaction. Secondly, with the help of the large amount reactive carboxylic acid groups, polyethyleneimine (PEI) were chemically grafted onto the surface by the reaction between amine group and acrylic acid group. Finally, zero-valent copper was reduced by sodium borohydride (NaBH4) and coated on the surface of polymer foam. Thus the copper functionalized porous adsorbent (Cu0–PEI–PAA) was constructed, and then applied for removing Cr(VI) from aqueous solution. The removal mechanism of Cr(VI) involved redox reaction by zero-valent copper and adsorption by amine groups, simultaneously. As a result, 99.5% of Cr(VI) could be removed within 2h, and the maximum removal capacity for Cr(VI) of Cu0–PEI(1800)–PAA was 9.16mg/g. Furthermore, the effect of initial concentration of Cr(VI), pH value, and temperature on the Cr(VI) removal was investigated. Therefore, the as-prepared zero-valent copper-loaded polymer foam could be an efficient and promising remediation material to remove Cr(VI) from wastewater.


      PubDate: 2015-05-11T21:29:20Z
       
  • 1,3,5-Triazine-pentaethylenehexamine polymer for the adsorption of
           palladium (II) from chloride-containing solutions
    • Abstract: Publication date: March 2015
      Source:Reactive and Functional Polymers, Volume 88
      Author(s): Merve Sayın , Mustafa Can , Mustafa İmamoğlu , Mustafa Arslan
      A triazine-hexamine (TAPEHA) polymer demonstrating high acid-resistance, good affinity to noble metals, and a high density of amine and triazine functional groups has been designed and synthesized. The obtained polymer was used as an adsorbent for the recovery of palladium (II) ions from chloride-containing solutions. Effects of pH, pCl, contact time, initial Pd(II) concentration, and temperature on adsorption were investigated and optimized by batch adsorption experiments. The pseudo second-order kinetic equation provides the best correlation for the process. While five isotherms were used, the nonlinear resolution of the Langmuir isotherm equation has been found to provide the closest fit to the equilibrium data. The monolayer adsorption capacity which is highest among literature is 517.2mg/g. All thermodynamic parameters suggest that Pd(II) adsorption onto TAPEHA particles is a spontaneous, physisorptive, and exothermic process. The formation of TAPEHA and Pd-adsorbed TAPEHA has been characterized by FE-SEM, EDAX, XRD, and FTIR instrumentations. Adsorption of the negatively charged chloropalladium (II) species mostly takes place via ligand exchange mechanism. Ease of synthesis and low cost, coupled with highly efficient and rapid removal of Pd(II) ions, make TAPEHA an attractive adsorbent.


      PubDate: 2015-05-11T21:29:20Z
       
  • Synthesis and antimicrobial activities of acrylamide polymers containing
           quaternary ammonium salts on bacteria and phytopathogenic fungi
    • Abstract: Publication date: March 2015
      Source:Reactive and Functional Polymers, Volume 88
      Author(s): Anqiang Zhang , Qiongqiong Liu , Yufeng Lei , Shuanghao Hong , Yaling Lin
      Three series of acrylamide monomers/polymers containing quaternary ammonium salts (QASs), i.e., acrylamide QAS monomers (QDs), homopolymers of QDs (PQDs) and copolymers of QDs with acrylate monomer (PQDCs), were synthesized and employed in antimicrobial tests against both bacteria (Escherichia coli (E. coli) and Staphylococcus albus (S. albus)) and phytopathogenic fungi (Rhizoctonia solani (R. solani) and Fusarium oxysporum f. sp. cubense race 4 (Foc4)). The antibacterial activity of the QASs was evaluated by determining the minimum inhibitory concentration (MIC) against E. coli and S. albus by the TTC coloration method, and the antifungal activity was measured by mycelia growth inhibition as well as MIC and the minimum fungicidal concentration (MFC) values. The results indicated that PQD homopolymers and PQDC copolymers showed far better antimicrobial activities than QD monomers. PQDC copolymers by incorporating hydrophobic acrylate units into the main chain of polyacrylamide backbone displayed even better antimicrobial activities, depending on QAS structure and hydrophobic content. Moreover, polymers with benzyl group attached to nitrogen atom showed better inhibitory effect on bacteria and phytopathogenic fungi. The results could assist understanding and development of future design of antimicrobial polymers as potential fungicide agents to control plant disease.


      PubDate: 2015-05-11T21:29:20Z
       
  • Chemical surface functionalization of bulk poly (p-phenylene sulfide)
           yields a stable sulfonic acid catalyst
    • Abstract: Publication date: March 2015
      Source:Reactive and Functional Polymers, Volume 88
      Author(s): Niklas Zwettler , Jakob S. Engbæk , Rasmus Lundsgaard , Irena Paranowska , Tina E. Nielsen , Stuart Clyens , Jens Christiansen , Morten Ø. Andersen
      Catalytic materials are important in industrial chemistry; these materials must be inexpensive and easy to process as well as resistant to chemicals, heat and structural loads. Poly (p-phenylene sulfide) (PPS) is a widely used and exceptionally resistant thermoplast. We demonstrate that the superficial regions of polymerized bulk PPS can be sulfonated using either SO3 or acetyl sulfate, yielding a solid core of unaltered PPS with a sulfonic acid-functionalized surface. The SO3 method was the most efficient and achieved 0.9mmol H+ per gram of polymer. We show that the sulfonated surfaces function as durable solid acid catalysts for the dehydration of ethanol to diethyl ether. We also develop a simple method for the formation of porous PPS structures based on compression molding and porogen leaching. Based on these results, we suggest that surface functionalization of bulk PPS can be used to develop a novel class of moldable, easily produced and durable heterogeneous catalysts.


      PubDate: 2015-05-11T21:29:20Z
       
  • Editors and Editorial Board
    • Abstract: Publication date: February 2015
      Source:Reactive and Functional Polymers, Volume 87




      PubDate: 2015-05-11T21:29:20Z
       
  • Quantification of singlet oxygen generation from photodynamic hydrogels
    • Abstract: Publication date: February 2015
      Source:Reactive and Functional Polymers, Volume 87
      Author(s): Rebecca A. Craig , Colin P. McCoy , Áine T. De Baróid , Gavin P. Andrews , Sean P. Gorman , David S. Jones
      Recently, we described a series of novel porphyrin-impregnated hydrogels capable of producing microbicidal singlet oxygen (1O2) on photoactivation. Indirect assessment of the efficacy of 1O2 production from such hydrogels has been previously described using microbiological techniques, but here we report a novel, direct method of quantification. Anthracene-9,10-dipropionic acid (ADPA) is known to irreversibly form an endoperoxide on reaction with 1O2, causing photobleaching of its absorbance band at approximately 378nm. Here, the reaction of this probe is exploited in a novel way to provide a simple, inexpensive, and convenient measurement of 1O2 generation from the surface of porphyrin-incorporated photosensitising hydrogels, with the ability to account for effects due to hydrogel porosity. Ingress of the probe into the materials was observed, with rates of up to 3.83×103 s−1. This varied by up to 200-fold with material composition and surface modification. Rates of 1O2 generation in these porphyrin-incorporated hydrogels, after compensating for ADPA ingress, ranged from 1.86×103 to 5.86×103 s−1. This work demonstrates a simple and straightforward method for direct 1O2 quantification from porous materials, with general utility.


      PubDate: 2015-05-11T21:29:20Z
       
  • Adsorption and recognition of protein molecular imprinted calcium
           alginate/polyacrylamide hydrogel film with good regeneration performance
           and high toughness
    • Abstract: Publication date: February 2015
      Source:Reactive and Functional Polymers, Volume 87
      Author(s): Kongyin Zhao , Tian Chen , Beibei Lin , Wenkui Cui , Bohong Kan , Ning Yang , Xiangyu Zhou , Xinxin Zhang , Junfu Wei
      Protein imprinted calcium alginate/polyacrylamide hydrogel film (CA/PAM MIP) with high toughness was prepared using bovine serum albumin (BSA) as template molecule, sodium alginate and acrylamide as functional monomers, N,N′-methylenebisacrylamide (MBAA) as the covalent cross-linker and CaCl2 as the ionic cross-linker via UV radiation-reduced polymerization. Factors affecting the adsorption capacity and imprinting efficiency of the BSA-imprinted CA/PAM hydrogel films were investigated, such as ratio of polyacrylamide/sodium alginate, film thickness, MBAA concentration and CaCl2 concentration. Results showed that the CA/PAM MIP exhibited an obvious improvement in terms of adsorption capacity for BSA compared with non-imprinted polymer (NIP). The adsorption capacity of MIP for BSA reached 22.49mg/g, which was 2.7times higher than NIP. The regeneration property of the BSA-imprinted CA/PAM hydrogel was distinctly improved and the imprinting efficiency of CA/PAM MIP maintained 77.95% of the initial value after five repetitions. Single and binary proteins rebinding indicated that the CA/PAM MIP exhibited good recognition performance. Cell culture experiments showed CA/PAM MIP was more suitable for cell culture than CA/PAM NIP. The residual sodium dodecyl sulfate (SDS) in the elution process leaded to the death of mouse fibroblast cells (L929) after 3days. A moderate elution solution without residue eluent should be used to prepare MIP for cell culture.


      PubDate: 2015-05-11T21:29:20Z
       
  • Preparation and swelling behaviors of a high temperature resistant
           superabsorbent using tetraallylammonium chloride as crosslinking agent
    • Abstract: Publication date: February 2015
      Source:Reactive and Functional Polymers, Volume 87
      Author(s): Xiaoyun Zhang , Xiangpeng Wang , Liang Li , Sisi Zhang , Ruonan Wu
      A new high temperature resistant superabsorbent was synthesized through solution polymerization of acrylamide (AM) and partially neutralized acrylic acid (AA), using tetraallylammonium chloride (TAAC) as crosslinker, ammonium persulfate (APS) as initiator. Parameters that influence water absorbency of the superabsorbent at 25°C and 200°C such as molar ratios of AM to AA, TAAC to AA, APS to AA and neutralization degree, were investigated. Swelling behaviors of superabsorbent prepared at the optimum conditions in different pH and saline solutions were studied. The swelling ratios of superabsorbent in distilled water and 1wt% NaCl solution at 250°C reach 287g/g and 69g/g, respectively.


      PubDate: 2015-05-11T21:29:20Z
       
  • Imidazolium salts grafted on cotton fibres for long-term antimicrobial
           activity
    • Abstract: Publication date: February 2015
      Source:Reactive and Functional Polymers, Volume 87
      Author(s): Boris Izmaylov , Diana Di Gioia , Galy Markova , Irene Aloisio , Martino Colonna , Valery Vasnev
      New antimicrobial (AM) coatings based on imidazolium salts have been prepared linking the imidazolium salts to the cotton fabric using siloxane oligomers as coupling agents. Three different imidazolium salts, linked to the siloxane oligomers connected to the cotton fabric either with ionic or covalent linkages, have been used. FTIR analysis shows that the imidazolium salts are linked to the cotton fabric. All the coatings prepared have high antimicrobial activity at both concentrations tested (3 and 10wt%) and against a Gram positive and a Gram negative bacterium. The AM activity is mainly retained after 4 cycles of washing.


      PubDate: 2015-05-11T21:29:20Z
       
  • Separation of butyric acid in fixed bed column with solvent impregnated
           resin containing ammonium ionic liquid
    • Abstract: Publication date: February 2015
      Source:Reactive and Functional Polymers, Volume 87
      Author(s): Marek Blahušiak , Štefan Schlosser , Július Annus
      Batch equilibrium and fixed bed column extraction experiments for the extraction of butyric acid (BA) into solvent impregnated resin (SIR) have been done. Microporous Amberlite XAD-1180N was impregnated with an ammonium ionic liquid (IL) trialkylmethylammonium bis(2,4,4-trimethylpentyl)phosphinate. The BA extraction capacity isotherm has not a Langmuir type shape and no finite capacity was observed. The loading of the impregnated IL with the extracted BA at 37°C is in agreement with the loading from L/L extraction equilibrium of BA at 25°C. Capacity of freshly prepared SIR particles is superior to classical porous ion-exchangers. Both the temperature and the superficial velocity in column influence the shape of the breakthrough-curve in fixed bed extraction of BA using SIR. Sharpening of the breakthrough curve was observed with the increasing temperature and decreasing superficial velocity. Stripping with water is not efficient for the regeneration of the loaded column after extraction because of low concentration of the product acid in the obtained effluent. Higher BA concentration was achieved by stripping with 0.15kmolm−3 and 0.075kmolm−3 NaOH solutions. The combination of initial water stripping coupled with consecutive stripping by alkali can be beneficial for decreasing the consumption of chemicals and further processing of the product. After two extraction/stripping cycles, a stable capacity was achieved and sustained for 14cycles, showing the possibility of long-term application of the prepared SIR in real technology.


      PubDate: 2015-05-11T21:29:20Z
       
  • Urease-carrying electrospun polyacrylonitrile mat for urea hydrolysis
    • Abstract: Publication date: February 2015
      Source:Reactive and Functional Polymers, Volume 87
      Author(s): Aref Daneshfar , Takeshi Matsuura , Daryoush Emadzadeh , Zahra Pahlevani , Ahmad Fauzi Ismail
      Electrospinning was used to fabricate beadless microfibrous polyacrylonitrile (ePAN) mats with an average fiber diameter of 1448±380nm from a 10wt.% PAN in dimethylformamide (DMF) dope solution at applied voltage of 18kV and 20cm fiber collection distance. Urease (EC 3.5.1.5) was then covalently immobilized on dispersed microfibrous ePAN mats following the chemical treatment of fibers with ethylenediamine (EDA) and glutaraldehyde (GA). The optimal concentration of GA for immobilization was 5%. The amount of loaded urease reached 157μg/mg mat, exhibiting 54% of the free urease activity. The surface chemistry of as-spun and chemically treated fibers was examined with Fourier transform infrared (FTIR) spectroscopy. Field emission scanning electron microscopy (FESEM) was used to study the morphology and diameter of the pristine, chemically treated, and urease-immobilized microfibrous mats. Immobilized urease showed increased temperature for maximum activity (from 37 to 50°C for free and immobilized urease, respectively) and improved storage stability (20days). The immobilized urease was also less sensitive to the changes in pH, especially in acid conditions. In addition, nearly 70% of initial activity of the immobilized urease was retained after 15 cycles of reuse, which proved the applicability of the electrospun fibers as successful enzyme carriers.


      PubDate: 2015-05-11T21:29:20Z
       
  • Synthesis and ion responsiveness of optically active polyacetylenes
           containing salicylidene Schiff-base moieties
    • Abstract: Publication date: February 2015
      Source:Reactive and Functional Polymers, Volume 87
      Author(s): Chunyu Zhang , Yu Zhang , Hexin Zhang , Yanming Hu , Xuequan Zhang , Toshio Masuda
      Acetylenic monomers containing salicylidene Schiff-base groups (1a and 1b) as well as Schiff-base and hydroxy groups (1c) were synthesized and polymerized with [(nbd)RhCl]2/Et3N catalyst to afford the corresponding polymers 2a–c with high molecular weights (Mn =2.6–7.2×105) in high yields (75–97%). Polarimetric, circular dichroism (CD), and UV–vis spectroscopic analyses indicated that the polymers formed helical structures with a predominantly one-handed screw sense. The addition of metal ions to salicylidene Schiff-base-containing polymers 2a and 2b produced insoluble polymer/metal complexes through ionic cross-linking as a result of salicylaldimine–metal ion complexation. Polymers 2b and 2c underwent a helix–coil transition upon the addition of HSO4 −, whereas these polymers did not exhibit responsiveness to other anions, such as F−, Cl−, and Br−.


      PubDate: 2015-05-11T21:29:20Z
       
  • Allylimidazolium salt based antibacterial polymer coatings produced by
           thiol–ene photocuring
    • Abstract: Publication date: February 2015
      Source:Reactive and Functional Polymers, Volume 87
      Author(s): Mirinae Kim , Chiman Song , Dong Keun Han , Kwang-Duk Ahn , Seung Sang Hwang , Dong June Ahn , Man-Ho Kim
      Photocurable formulations containing trifunctional thiol, trifunctional ene, and antibacterial allylimidazolium salts have been employed for transparent antibacterial coatings. The antibacterial component 1-allyl-3-dodecylimidazolium salt (ADIm) is prepared and chemically attached to polymer networks using a one-step thiol–ene photocuring reaction. Ultra-small (USANS) and small angle neutron scattering (SANS) measurements show that the photocured polymers are loosely networked three-dimensional structures with a mass fractal of approximately 2.7±0.2. The minimum inhibitory concentration (MIC) for the ADIm was determined to be 500μg/ml and 15.63μg/ml for Escherichia coli (Gram negative) and Staphylococcus aureus (Gram positive) bacteria, respectively. Coating formulations containing 10mol% of the antibacterial ADIm photocured on glass substrates showed strong antibacterial activity against environmental bacteria such as E. coli and/or S. aureus.


      PubDate: 2015-05-11T21:29:20Z
       
  • Editors and Editorial Board
    • Abstract: Publication date: January 2015
      Source:Reactive and Functional Polymers, Volume 86




      PubDate: 2015-05-11T21:29:20Z
       
  • Editorial “Polymers for membrane applications”
    • Abstract: Publication date: January 2015
      Source:Reactive and Functional Polymers, Volume 86
      Author(s): Alexander Bismarck , Kang Li , Andrew Livingston



      PubDate: 2015-05-11T21:29:20Z
       
  • Targeted gas separations through polymer membrane functionalization
    • Abstract: Publication date: January 2015
      Source:Reactive and Functional Polymers, Volume 86
      Author(s): Melinda L. Jue , Ryan P. Lively
      Gas separation membranes have been studied for several decades and are starting to find commercial acceptance. This review will focus on polymer functionalization to improve gas separation performance, namely, permeability, permselectivity, or both. The review will cover both “diffusivity controlled” and “solubility controlled” functionalization strategies; each strategy refers to the different mode of gas transport through the membrane. Diffusivity controlled functionalization strategies mainly involve control over free volume elements in amorphous polymers via promotion or inhibition of chain packing through functional groups. As such, the effects of this functionalization are typically confined to the well-known selectivity/permeability tradeoff. Solubility controlled modification strategies utilize functional groups that have strong chemical interactions with some of the penetrant molecules and offers an enhanced solution-diffusion or a non-solution-diffusion permeation pathway. This functionalization can potentially exceed the Robeson upper bound, but is often challenged by impurities and deactivation of the chemical functionality.


      PubDate: 2015-05-11T21:29:20Z
       
  • Water vapor and CO2 transport through amine-containing facilitated
           transport membranes
    • Abstract: Publication date: January 2015
      Source:Reactive and Functional Polymers, Volume 86
      Author(s): Zi Tong , Varun K. Vakharia , Michael Gasda , W.S. Winston Ho
      Amine-containing CO2 facilitated transport membranes have great potential to be applied for hydrogen purification from synthesis gas. In some applications, the humidity of the retentate stream is required as well as the purity of hydrogen. The membranes are highly hydrophilic, and they exhibit not only high CO2 permeance but also high water vapor permeance. In this work, the transport of water vapor and CO2 through the membranes composed of an amine-containing selective layer and a microporous polysulfone substrate was investigated. From the experiments conducted, water vapor permeance appeared to be independent of the selective layer thickness, indicating that the substrate is the controlling factor of the mass transfer resistance to water vapor transport. Moreover, water vapor permeance appeared to reduce linearly with increasing the number of the substrate layers. But, CO2 permeance and CO2/H2 selectivity did not change significantly as the number of the substrate layers increased. These results indicated that the CO2 separation performance is governed by the selective layer as expected. In addition, the membranes synthesized from Lupamin® containing 34% polyvinylamine and 66% salt (sodium formate) demonstrated better CO2 separation performance than those from pure polyvinylamine, presumably due to better water retention capability of the salt than polyvinylamine.


      PubDate: 2015-05-11T21:29:20Z
       
  • Impact of preparation method on physical properties and gas separation
           performance of fluorinated copolymer membranes
    • Abstract: Publication date: January 2015
      Source:Reactive and Functional Polymers, Volume 86
      Author(s): Soon-Chien Lu , Ivo F.J. Vankelecom
      Two batches of poly(vinylidene fluoride–hexafluoropropylene) [P(VDF–HFP)] copolymer with different monomer ratios were thoroughly characterised and cast into membranes to relate the fundamental properties of this copolymer with its performance in CO2 separation. Solubility testing revealed that the PVDF part of the copolymer was dominating and calculations with Hansen’s solubility parameters corroborated the outcome. A very slow solvent evaporation rate and use of solvents with a high boiling point were found to be essential in the formation of defect-free membranes from this copolymer for gas separations. Physical examination, DSC, XRD and TGA were also performed to better link the fundamental membrane properties to the gas separation performance. A low crystallinity in the prepared P(VDF–HFP) membranes was favourable in terms of compatibility, solubility, membrane formation and CO2 separations.


      PubDate: 2015-05-11T21:29:20Z
       
  • Functionalization of POSS nanoparticles and fabrication of block copolymer
           nanocomposite membranes for CO2 separation
    • Abstract: Publication date: January 2015
      Source:Reactive and Functional Polymers, Volume 86
      Author(s): Md. Mushfequr Rahman , Volkan Filiz , Muntazim Munir Khan , Bahadir N. Gacal , Volker Abetz
      Synthesis of methoxy poly(ethylene glycol) (PEG) functionalized polyhedral oligomeric silsesquioxane (POSS) nanoparticles via epoxy ring opening reaction in three different solvents are outlined in this manuscript. The nanoparticles are used as filler for commercial poly(ether-block-amide) multiblock copolymer PEBAX® MH 1657. The influence of two novel structural features of the synthesized nanofillers on the gas separation performance of nanocomposite membranes are studied on the examples of CO2/N2 and CO2/H2 gas pairs. These are – (i) presence of a dimethylsilyl group as spacer between the cage structure of POSS and the PEG ligand and (ii) formation of a tetrahydrofuran (THF) complex. While ideal selectivity characteristics for the matrix polymer are not significantly affected by the presence of fillers, the single gas permeability (determined by time-lag method) is remarkably increased in both cases.


      PubDate: 2015-05-11T21:29:20Z
       
 
 
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